Tinea capitis caused by Trichophyton violaceum in an immunocompetent elderly patient: A case report and review of literature

Abstract Tinea capitis is a common dermatophyte infection of the scalp in children. It is an uncommon infection in adults and usually affects postmenopausal women and immunocompromised patients. We report an immunocompetent elderly female with inflammatory tinea capitis caused by Trichophyton violaceum and review the literature for the past 5 years to describe the disease, its epidemiologic characteristics, dermatophyte species involved and treatment options used. The total number of cases was 11, including 8 women and 3 men, with an average age of 48.36. The most commonly isolated dermatophyte was Trichophyton tonsurans, and most cases were treated successfully with oral terbinafine with no side effects. In our case, the diagnosis was established by direct examination, culture and histological examination. Remedy with itraconazole and prednisolone was very successful. Early diagnosis of tinea capitis in adults is necessary to provide early treatment and minimize sequelae of the disease.


| INTRODUCTION
Tinea capitis is a common infection of the scalp and hair caused by dermatophyte fungi that principally affects children. 1 It is an uncommon infection in adults and generally occurs in postmenopausal women and immunocompromised patients, e.g., AIDS patients, transplant recipients, patients receiving high-dose steroid therapy, and patients with diabetes mellitus. 2,33][4] The causative pathogens in children and adults belong to two genera: Trichophyton and Microsporum. 5The clinical manifestations are characterized by an erythematous and scaly plaques, itching, suppurative swelling with purulent discharge, areas of alopecia, and regional lymphadenopathy.It is often misdiagnosed as a bacterial infection, leading to unnecessary antibiotic prescription or surgical intervention.Treatment delay may result in permanent hair loss. 6,7The diagnosis of tinea capitis is made by fungal culture (gold standard), microscopy, wood's lamp, and trichoscopy. 5,8he had been treated with multiple oral antibiotics and a topical cream consisting of clobetasol and salicylic acid for 1 month at another clinic, which worsened the patients' symptoms.The patient had no medical history other than hypertension.She was in a good general condition and had not received any immunosuppressant drug.There was not any similar disease in other family members.Physical examination showed multiple erythemato-edemathous papules and plaques with yellow crust, pustule formation, and hair loss involving the vertex and occipital area of the scalp (Figure 1).There were no other lesions in any other parts of the skin, nails, and mucosa.Laboratory examination revealed a: fasting blood sugar (FBS) = 94 mg/ dL, urea = 44 mg/dL, serum creatinine (SCr) = 0.9 mg/dL, serum glutamic-oxaloacetic transaminase (SGOT) = 23 IU/ dL, serum glutamic pyruvic transaminase (SGPT) = 19 IU/ dL, alkaline phosphatase (ALP) = 121 U/dL, erythrocyte sedimentation rate (ESR) = 37 mm/h, and C-reactive protein (CRP) = 0.6 mg/dL.The complete blood count (CBC) and the serum electrolyte tests were normal.The viral serology and the interferon-g release assay (IGRA) were negative.The clinical differential diagnosis included pemphigus vulgaris, folliculitis decalvans, erosive pustular dermatosis, and tinea capitis.First, we performed a dermoscopy, and the presence of "comma", "corkscrew," and dystrophic broken hairs was the clue for the diagnosis of tinea capitis.Then, according to the results of the dermoscopy, we performed a KOH smear and culture.The direct exam with 20% KOH showed an endothrix infection, and the mycological culture showed the growth of Trichophyton violaceum.Bacterial culture was negative.Skin biopsy of the scalp lesions showed an acute superficial and deep folliculitis with intrafollicular mycelial fungal infection consistent with tinea capitis (endothrix), on hematoxylin and eosin staining (Figure 2A,B).PASstained slides showed endothrix septate hyphae invading the hair shafts (Figure 2C).Fluorescent microscopy showed endothrix infection by green fluorescent, septate hyphae, and spores (Figure 2D).The patient was treated with prednisolone 15 mg daily for 1 month and oral itraconazole 400 mg daily, which was gradually tapered to 100 mg daily at the last 2 months.The liver and renal function tests were evaluated regularly during the treatment period, and all were in the normal ranges.Also, the patient and all family members were treated with 2.5% selenium sulfide shampoo.There was complete clearance of the lesions and acceptable hair regrowth (Figure 3).

| DISCUSSION
The amount of fungistatic saturated fatty acids in sebum increases at puberty and therefore dermatophyte colonization of the scalp disappears in this age. 9This is thought to explain the rarity of tinea capitis in adults.3][4] Our patient was a 75-yearold menopause female, but not immunocompromised.In most of the reported cases, including our case, the diagnosis was delayed.This delay is probably due to both the rarity of this infection in adults and its atypical clinical presentation.The disease may resemble bacterial folliculitis, folliculitis decalvans, dissecting cellulitis, pityriasis amiantacea and its related etiologies, and scaring alopecia like lupus erythematosus. 10In many studies, the correct diagnoses were established by tissue culture. 3,43][4] Due to the numerous reports describing treatment-resistant dermatophytosis, which has emerged as a global public health threat, [11][12][13][14] we started the treatment with high-dose itraconazole as 400 mg daily.Also, we prescribed prednisone 15 mg daily at the first month because of the severe inflammation.Our patient responded F I G U R E 1 Erythematous papules and plaques over the scalp of an elderly female, with yellow crust, pustule formation, and hair loss.
well to this treatment, and there complete clearance of the lesions with acceptable hair regrowth.
We reviewed tinea capitis case reports in adults indexed in PubMed between 2018 and 2023.To be included in the review, articles had to be available in the English language.Inclusion criteria included patient age ≥18 years, diagnosis of tinea capitis, no history of immunosuppression or receiving any immunosuppressant drugs, no history of other medical conditions or history of other dermatophytosis infection in other parts of the skin, no history of gardening, pet-keeping, contact with domestic animals, or other individuals with the same manifestations or dermatophytosis infection, and no history of contact with objects containing fomites, including brushes, combs, bedding, clothing, toys, furniture, and telephones (Table 1).
We found a total of 11 cases.Of these cases, the prevalence was higher in women (8/11) and the average age was 48.36.Three cases did not have a mycological culture and did not mention the dermatophyte isolated.Trichophyton tonsurans was the most common dermatophyte, followed by Trichophyton violaceum.Most cases were treated with oral terbinafine 250 mg daily.One patient was treated with oral griseofulvin 500 mg every 12 h and another one with oral itraconazole 200 mg twice daily.Most patients received combination therapy consisting of oral and topical antifungal agents.All patients reported were cured successfully without any side effects.Two cases had disseminated lesions on the face, 15 extremities, and nails 15,17 years after the scalp manifestations.One case caused by Trichophyton tonsurans suffered subsequent herpes zoster infection, which shows that tinea capitis may be a risk factor for varicella zoster virus reactivation.

F I G U R E 2
Tinea capitis.(A and B) Septate hyphae and spores invading the hair shaft of disrupted hair follicle (hematoxylin and eosin staining, ×100 (A) and ×400 (B)).(C) Endothrix septate hyphae invading the hair shaft (PAS staining, ×400).(D) Endothrix hair infection by green fluorescent septate hyphae and spores (Fluorescent microscope, ×100).F I G U R E 3 Hair regrowth and complete clearance of all inflammatory lesions.T A L E 1 Tinea capitis case reports in adults from 2018 to 2023. 16 CONCLUSIONHerein, we report a case of tinea capitis in a 75-year-old immunocompetent female and review the literature on this rare entity from 2018 to 2023.Despite the rarity of the disease in adults, tinea capitis should be included in the differential diagnosis of the inflammatory scalp lesions in adult or elderly patients, even in immunocompetent individuals.A dermoscopy and a KOH examination (and/or fungal culture) should be performed, to provide early and accurate treatment to minimize complications and sequelae of the disease.